Radiation therapy hypothyroidism with

Tertiary hypothyroidism, or hypothalamic hypothyroidism, results from impaired TRH stimulation of pituitary TSH. This may be due to a disorder that damages the hypothalamus or interferes with hypothalamic-pituitary portal blood flow, thereby preventing delivery of TRH to the pituitary. Tumors, trauma, radiation therapy, or infiltrative disease of the hypothalamus can cause such damage. This relatively rare form of hypothyroidism is also characterized by inappropriately low levels of serum TSH. 

In untreated women, the main risk factors for endometrial carcinoma are age, obesity, nulliparity, late menopause (and possibly early menarche), the Stein-Leventhal syndrome, exposure to exogenous estrogens, radiation, and certain systemic diseases, including diabetes mellitus, hypertension, hypothyroidism, and arthritis (SED-14, 1451) (88). Certain of these risk factors indicate that an altered endocrine state with increased estrogen stimulation is a predisposing cause, and one might thus in theory expect estrogen treatment (and notably hormonal replacement therapy) to increase the risk (SEDA-22, 466). 

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